Got my Arthas. Redline can confirm
. A big tip I figured out after my first 2x wins... you can play WILD decks :P
Here is how I went about it...
NOTE: If you play doomslayer on your turn 7 you will basically take 5 to the face and bypass the whole stage 2. (although for warrior or paly you don't want to do that)
Druid: Played standard jade druid from ladder(not even wild based). Took 1-2 times
Priest: Played standard control Kaz priest (not wild). Took 1 time
Hunter: This one took a while. Play heavy spells that generate minions(secrets, etc) Couple strats here. You can go 2x molten giants with sunfury and then a couple hyneas. This gives you some mass damage early on. You should get molten on draw. You basically have to beat him before stage 2(frostmourne)
Warlock: Run a reno lock here. Molten, big bodies, etc. You want lots of board removal and demons. Jaxx, lich hero, reno are a near must. You also need to run Mulganis. This one was really hard for me, took at least a dozen tries.
Mage: Basically run lots of secrets. you want 2x molten giants again and then the more standard "exodia" combo (sorceress, copy spell, old man fireball) You want to run mana bind secret and counter spell. Blizzard/frost nova/doomsayer as well. You basically should "reset" until you get the 2/1 minion that gives you a free secret that turn(looks like a chicken thing) and mana bind or counter spell. You can counter his spell to set you to 1 life. From there, control and draw until you can build up the exodia combo. Use blizzard/frost nova + doomsayer to get past stage 2. This one is medium hard. took me like 6-7 tries. And that's after getting those perfect starting hands.
Warrior: Easiest one cuz of a semi-bug/way it works. You want 2x public defenders, Kul'Thezad, 2x brawls, 2x scaled nightmares. 2x executes, some more taunts, lots of armor up and card draw (think heavy control warrior). Basically then you do this...
1. Control board in stage 1
2. stage 2 - brawl an empty board so you leave one bad guy
3. Draw/armor up until you can play defender + kul on one term
4. he will just mill cards and not want to kill the defender, when he does, it will come back
5. while he is goofing off, drop a scaled nightmare and let it build up enough to be more than his health+armor
6. once #5 is good, kill off the last bad guy with your kul and then OTK him
Paly: You basically use the OTK paly lich strat here. I don't have the legendary that refreshes your hero power so i went at it this way.... you need lich paly, 2x righteous protector, 2x desperate stand, garrison commander., 1x enter the coliseum. And then you want a whole bunch of minions with deathrattles that help you and you want board clear. ie. Mistress, Zombie Chow, doomsayer, conceration+equality, or equality+pyro. Weapons too. Then you should be able to do this...
1. Control board until stage 2. Once stage 2 starts, play Enter the coliseum with one minion on board.
2. keep the heal up and "tank" the damage until you can play the lich paly
3. next turn play 1x righteous, cast stand on it, garrionson, 2x hero power (2 horse). He will kill the protector, make sure you have a weapon or some way to clear it so you leave only 1 protector, if you need it. Just keep count of the "shots" your protector can take. 1 protector with 1 stand on it is 4 shots.
4. next turn, 2x hero power (win)
never leave stage 2 as he won't do much other than kill your protector over and over.
Rogue: He gets rid of your spells. So take 2x counterfeit coins and that is all. The rest, fill up with nothing but murlocs. Go Face, beat before turn 7. Old-Eye is needed and gentle megasaurs. SMOrc. This one took a couple times, but was not bad.
Shaman: *Extremely* similar to rogue. Heavy murlocs, but take some totems (flametongue, primal fin) Use the new spell that draws out murlocs too. Take some de-evolves for taunts. Old-eye is huge here, and so are gentle megasaurs. More SMOrc. Again, couple times. You just have to get that killer starting hand that we all hate (when we play against Face murloc decks)
In both rogue and shaman, Old-Eye is huge and so is megasaurs. Sir finley helped me win the rogue match by getting healing as a hero power and keeping my board solid.
Sorry I didn't take deck screenshots, but the strats worked for me. Good luck!